Scatter plot data different resolution satellite images

I have two satellite images with different resolution and I would like to do a scatter plot comparing each pixel for the same latitude and longitude. I have both images in netcdf format, which is correspondent latitude, longitude and band information (in this case Reflectance at 859 nm). Any ideas on how I could do this in matlab? I have inserted an image showing what I want to obtain (Vanhellemont & Ruddick 2015).

[Walter Roberson]

The image did not get inserted :(

Is the scale large enough that curvature of the Earth must be worried about, or can it be treated as flat rectangular?

[Walter Roberson]

duplicated by http://uk.mathworks.com/matlabcentral/answers/223239-scatter-plot-data-different-resolution-satellite-images